Serum Free Media
Serum-free cell culture media provide researchers with the ability to standardize their cell culture conditions by eliminating the need for undefined and highly variable serum products derived from human or animal sources, such as human AB serum or fetal calf serum (FCS).
The biological variability between serum batches often requires extensive pre-screening to identify one suitable for a specific application. Even brief exposure of PBMC to a mitogenic serum batch—for instance, during cell washing or freezing—can lead to elevated background levels in cytokine assays. Additionally, toxic or inhibitory serum batches can compromise assay integrity. Because of this variability, researchers often purchase large lots of serum to maintain consistency, which adds both cost and inconvenience. Every time a serum batch is changed, it introduces a significant and unpredictable variable, complicating test result comparison. Moreover, the infectious risks associated with serum are causing increased regulatory restrictions on international shipment and exchange of serum-exposed materials.
Given these challenges, there is growing pressure from both regulatory bodies and the scientific community to eliminate serum use and adopt defined, consistent alternatives. However, due to the complex nature of serum—rich in essential growth factors and nutrients—developing effective serum substitutes for primary cells, especially freshly-isolated human PBMC, has been difficult. While many serum-free media are adequate for robust tumor cell lines or hybridomas, PBMC demand much stricter conditions to preserve their viability and functionality in a serum-free environment.
In response, CTL has collaborated for years with U.S. governmental, industrial, and academic partners to standardize ELISPOT and other direct ex vivo cytokine assays using freshly-isolated or cryopreserved PBMC. These efforts have led to the development of the CTL Serum-free Media Platform, a comprehensive solution consisting of three product lines designed to support the four essential steps of working with human PBMC: washing, testing, freezing, and thawing—all traditionally dependent on serum.
Learn more about the low background and high signal performance of CTL’s serum-free media and how it can streamline and standardize your immune monitoring workflows.